本論文研究在一般玻璃基板上成長大面積平面顯示器用高性能銦鎵鋅氧化物雙通道透明薄膜電晶體。本元件使用射頻磁控濺鍍氧化鉿/氧化鋁(HfO2/Al2O3)作為堆疊絕緣層閘極。並濺鍍高載子濃度的氧化鋅鎵(GZO)作為元件的下閘極、源極與汲極。實驗顯示以氧化鉿/氧化鋁組成的雙層閘極絕緣能有效降低閘極漏電流。
利用具有低載子濃度以及比非晶矽高的載子移動率的非晶銦鎵鋅氧化物作為雙層通道中的上主動層可以讓電晶體有低的臨界電壓。下主動層則利用具有高載子移動率、較佳導電度的純氧化鋅來增加開電流(on-current)以提昇開關電流比(On/Off current ratio)。但傳統的ITO/a-IGZO雙通道薄膜電晶體，在退火後會因ITO再結晶，導致關電流提高使開關電流比下降。故本研究改用ZnO/a-IGZO做為雙通道主動層。實驗證實其電流開關比，臨界電壓及次臨界擺幅可分別達到1.37×107， 1.72Volt，及SS＝0.37V/dec。這些特性不但較單主動層為佳，且優於已報導的銦鎵鋅氧化物雙通道薄膜電晶體1×107的電流開關比，臨界電壓2.75Volt，SS＝1.22V/dec。
此外，又藉由退火可修復電晶體元件介面間的缺陷以降低臨界電壓。在250℃的溫度下退火10分鐘， ZnO/a-IGZO雙通道電晶體的臨界電壓可由1.72Volt下降至1.2Volt，電流開關比微幅增加至1.42×107，場效載子遷移率5.5 cm2/Vs，次臨界擺幅降至0.33 V/dec且透明度可保持>85%以上。

In this thesis, the high performance amorphous InGaZnO double channel full transparent thin film transistors (FTTFT) prepared on glass substrate were studied in details. We sputter the HfO2/Al2O3 as double gate dielectric layer and the high carrier concentration GZO for bottom gate and source/drain electrodes. Both HfO2 and Al2O3 are transparent high k dielectric, and used to decrease the gate leakage current.
We use low carrier concentration and higher carrier mobility amorphous InGaZnO as the top active layer to get low threshold voltage, and employ the high mobility and conductivity ZnO as button channel to increase on current. With the double channel structure, one can achieve very low off current and high on/off current ratio.
Compared to the traditional ITO/ a-IGZO double channel TFT, the developed ZnO / a-IGZO device can resistance a higher annealing temperature for improving on/off ratio and getting lower threshold voltage. As a result, better performances of 1.42×107, 1.2Volt, and 0.33V/dec respectively for on/off current ratio, threshold voltage and SS could be obtained. The performances not higher than the single channel counterpart, but also better than 1.37×107, 1.72Volt and 0.37V/dec respectively for the reported amorphous InGaZnO double channel one.
Besides, the higher temperature annealing could repair the interface defect, and thus lowering down the threshold voltage 1.2Volt, which is lower than the reported 3.25 V. The overall transparent is about 85%.

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